This is a three year study of vulnerability factors that may contribute to the development of alcohol dependence through the mechanism of stress dampening. Eighty moderate to heavy drinkers (40 males, 40 females), half with a history of familial alcoholism, will be studied in the natural environment using an intensive daily process methodology during a 50-day observational period. The study will examine family history of alcoholism, gender, and affective reactions to daily events as predictors of alcohol use. It is hypothesized that subjects with familial history of alcoholism will be more extreme in their affective reactions to negative events; exhibit greater dampening of these responses when alcohol is consumed prior to a stressful event; and report more alcohol use after experiencing such events.